Workers at a southwestern China plant of Foxconn, Apple's main manufacturer,
went on the rampage this week after a dispute in a restaurant turned
violent, a Chinese government website said.

Seven workers at a Foxconn factory in Chengdu went to a restaurant near their dormitory, but began making a ruckus after an argument between the eatery's owner and his wife "affected their meal", said a statement on the Sichuan government website released on Thursday.

After the restaurant owner called the police, the workers ran back to their dormitory shouting "they are beating us", upon which around 100 of their colleagues came in and joined the disturbance, throwing bottles, the statement added.

Police came and detained four drunken workers overnight, it added. There were no injuries.

"Foxconn is cooperating with local law enforcement authorities on their investigation into this incident," the company said in a statement.

Foxconn Technology Group, Apple's main global contract manufacturer run by Taiwanese tycoon Terry Gou and employing 1.2 million workers in China, has come under fire in recent years for running massive "sweatshops" to mass produce high-end iPads and iPhones.

Following a spate of critical reports detailing unsafe factory practices at Foxconn plants that have triggered worker deaths and suicides, Apple this year allowed the US-based Fair Labor Association to conduct a high-profile and extensive probe of Foxconn's China factories.

The report, released in March and based on 35,000 worker interviews, unearthed labour violations including extreme work hours and unpaid overtime. As a result, Apple and Foxconn pledged major improvements including cutting workloads, improving safety protocols and upgrading workers' housing and quality of life.